package com.heima.article.service.impl;

import com.alibaba.fastjson.JSON;
import com.heima.apis.wemedia.IWemediaClient;
import com.heima.article.mapper.ApArticleMapper;
import com.heima.article.service.HotArticleService;
import com.heima.common.constants.ArticleConstants;
import com.heima.common.redis.CacheService;
import com.heima.model.article.pojos.ApArticle;
import com.heima.model.article.vos.HotArticleVo;
import com.heima.model.common.dtos.ResponseResult;
import com.heima.model.wemedia.pojos.WmChannel;
import lombok.extern.slf4j.Slf4j;
import org.joda.time.DateTime;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.Date;
import java.util.List;
import java.util.stream.Collectors;

@Slf4j
@Service
@Transactional
public class HotArticleServiceImpl implements HotArticleService {

    @Autowired
    private ApArticleMapper apArticleMapper;

    /**
     * 计算热门文章
     */
    @Override
    public void computeHotArticle() {
        // 1. 查询前5天的文章数据
        Date dayParam = DateTime.now().minusDays(5).toDate();
        List<ApArticle> articleList = apArticleMapper.findArticleListByLast5days(dayParam);

        // 2. 计算文章的分值
        List<HotArticleVo> hotArticleVoList = getHotArticleVoList(articleList);

        // 3. 为每个频道缓存30条分值较高的文章
        cacheTagToRedis(hotArticleVoList);
    }

    @Autowired
    private IWemediaClient wemediaClient;

    @Autowired
    private CacheService cacheService;


    /**
     * 为每个频道缓存30条分值较高的文章
     * @param hotArticleVoList
     */
    private void cacheTagToRedis(List<HotArticleVo> hotArticleVoList) {
        // 为每个频道缓存30条分值较高的文章
        ResponseResult responseResult = wemediaClient.getChannels();
        if(responseResult.getCode().equals(200)){
            String jsonString = JSON.toJSONString(responseResult.getData());
            List<WmChannel> wmChannelList = JSON.parseArray(jsonString, WmChannel.class);
            // 检索出每个频道的文章
            if(wmChannelList!=null){
                for (WmChannel wmChannel : wmChannelList) {
                    List<HotArticleVo> hotArticleVos = hotArticleVoList.stream().filter(item ->
                        item.getChannelId().equals(wmChannel.getId())
                    ).collect(Collectors.toList());

                    // 给文章排序, 取30条分值较高的文章存入redis key: 频道id value: 30条分值较高的文章
                    sortAndCache(hotArticleVos, ArticleConstants.HOT_ARTICLE_FIRST_PAGE + wmChannel.getId());
                }
            }
        }

        // 设置推荐数据
        // 给文章排序, 取30条分值较高的文章存入redis key: 频道id value: 30条分值较高的文章
        sortAndCache(hotArticleVoList, ArticleConstants.HOT_ARTICLE_FIRST_PAGE + ArticleConstants.DEFAULT_TAG);
    }

    /**
     * 排序并且缓存数据
     * @param hotArticleVos
     * @param key
     */
    private void sortAndCache(List<HotArticleVo> hotArticleVos, String key) {
        hotArticleVos = hotArticleVos.stream().sorted(
                Comparator.comparing(HotArticleVo::getScore).reversed()
        ).collect(Collectors.toList());
        if(hotArticleVos.size() > 30){
            hotArticleVos = hotArticleVos.subList(0, 30);
        }
        cacheService.set(key, JSON.toJSONString(hotArticleVos));
    }


    /**
     * 获取热文章列表
     * @param articleList
     * @return
     */
    private List<HotArticleVo> getHotArticleVoList(List<ApArticle> articleList) {
        List<HotArticleVo> articleVoList = new ArrayList<>();
        if(articleList!=null) {
            for (ApArticle apArticle : articleList) {
                HotArticleVo hotArticleVo = new HotArticleVo();
                BeanUtils.copyProperties(apArticle, hotArticleVo);
                Integer score = computeArticleScore(apArticle);
                hotArticleVo.setScore(score);
                articleVoList.add(hotArticleVo);
            }
        }
        return articleVoList;
    }

    /**
     * 计算文章分数
     * @param apArticle
     * @return
     */
    public Integer computeArticleScore(ApArticle apArticle) {
        Integer score = 0;
        if(apArticle.getLikes() != null){
            score += ArticleConstants.HOT_ARTICLE_LIKE_WEIGHT*apArticle.getLikes();
        }
        if(apArticle.getComment() != null){
            score += ArticleConstants.HOT_ARTICLE_COMMENT_WEIGHT*apArticle.getComment();
        }
        if(apArticle.getCollection() != null){
            score += ArticleConstants.HOT_ARTICLE_COLLECTION_WEIGHT*apArticle.getCollection();
        }
        if(apArticle.getViews() != null){
            score += apArticle.getViews();
        }
        return score;
    }


}
